Minimally invasive surgery (MIS) is a broad encompassing term that includes keyhole type procedures from orthopedic joint repair to cardiac stent placement. MIS reduces collateral trauma by using tools inserted into the body through small incisions, which allows the patient to recover and resume a normal lifestyle quicker.
Laparoscopic MIS has been advanced by the introduction of the da Vinci surgical system by Intuitive Surgical, Inc. in the early 2000s. The da Vinci system is a tele-robotic system, which includes four robotic arms (that are external to the patient) that hold the laparoscope camera and instruments. Advantages of such surgical robotics include hand tremor reduction, additional articulations in surgical instruments end effectors, corrections for motion reversal, and motion scaling. However, since a da Vinci system is an extension of laparoscopy, it also suffers the inherit disadvantages of laparoscopy. First, these robots are situated outside the patient and, thus, remain subject to the dexterity limitations imposed by the use of long tools inserted through small incisions. Most studies suggest that current externally situated robotic systems offer little or no improvement over standard laparoscopic instruments in the performance of basic skills (Dakin, G. F. and Gagner, M., 2003. “Comparison of Laparoscopic Skills Performance Between Standard Instruments and Two Surgical Robotic Systems”. Surgical Endoscopy, 17(4), April, pp. 574-579; and Nio, D., Bemelman, W. A., den Boer, K. T., Dunker, M. S., Gouma, D. J., and van Gulik, T. M., 2002. “Efficiency of Manual vs. Robotical (Zeus) Assisted Laparoscopic Surgery in the Performance of Standardized Tasks”. Surgical Endoscopy, 16(3), March, pp. 412-415.) Furthermore, a limited range of motion for the robotic camera can still result in obstructed or incomplete visual feedback. Finally, a da Vinci system carries a significant price tag of approximately $1.5M (plus required inspection and scheduled maintenance costs), which limits such a system to be available only to larger hospitals. Currently, there are efforts focusing on developing next generation robots that improve mobility and sensing capability while reducing complexity and cost (Cavusoglu, M. C., Williams, W., Tendick, F., and Sastry, S. S., 2003. “Robotics for Telesurgery: Second Generation Berkeley/UCSF Laparoscopic Telesurgical Workstation and Looking Towards the Future Applications”. Industrial Robot: An International Journal, 30(1), January, pp. 22-29; Cavusoglu, M. C., Tendick, F., and Sastry, S. S., 2001. “Telesurgery and Surgical Simulation Haptic Interfaces to Real and Virtual Surgical Environments”. Touch in Virtual Environments, IMSC Series in Multimedia; Ang, W., 2004. Active Tremor Compensation in Handheld Instrument for Microsurgery. Tech Report SMU-R1—TR-04-28, Carnegie Mellon University, Pittsburgh, Pa., May; Riviere, C., Ang, W., and Khosla, P., 2003. “Toward Active Tremor Canceling in Handheld Microsurgical Instruments”. IEEE Transactions on Robotics and Automation, 19(5), October, pp. 793-800; and Rosen, J., Lum, M. Trimble, D., Hannaford, B., and Sinanan, M., 2005. “Spherical Mechanism Analysis of a Surgical Robot for Minimally Invasive Surgery—Analytical and Experimental Approaches”. Studies in Health Technology and Informatics, 111(1), January, pp. 422-428.)
In Vivo Laparoscopic Robots
As shown by the da Vinci system, the use of robots in MIS offers advantages, but these are limited when situating the robot outside the body. An alternative approach is to build smaller, low-cost, robotic devices or in vivo robots that can be placed inside the patient and near the surgical site.
A number of research groups are working on in vivo robotic devices for use in minimally invasive surgery. For example, a proof-of-concept design of an in vivo stereoscopic imaging system has been described by Miller et al. (Miller, A., Allen, P., and Fowler, D., 2004. “In vivo Stereoscopic Imaging System with 5 Degrees-of-Freedom for Minimal Access Surgery”. Studies in Health Technology and Informatics, 12(1), January, pp. 234-240.) A second generation single camera pan and tilt prototype based on this initial concept is described in Hu et al. (Hu, T., Allen, P. K., and Fowler, D. L., 2008. “In vivo Pan/Tilt Endoscope with Integrated Light Source”. Studies in Health Technology and Informatics, 132(1), January, pp. 174-179), and is currently being evaluated in ex vivo and in vivo tests. Finally, the HeartLander robot employs a suction-based drive to move across the surface of the beating heart. (Patronik, N., Zenati, M. A., and Riviere, C., 2005. “Preliminary Evaluation of a Mobile Robotic Device for Navigation and Intervention on the Beating Heart”. Computer Aided Surgery, 10(4), April, pp. 225-232; and Patronik, N., Zenati, M. A., and Riviere, C., 2004. “Crawling on the Heart: A Mobile Robotic Device for Minimally Invasive Cardiac Interventions”. MICCAI, 3217, pp. 9-16.)
Others have previously developed a family of in vivo fixed-base and two-wheeled mobile robots (30 cm3), and demonstrated that they can successfully operate within the insufflated abdominal cavity. (Rentschler, M., Iagnemma, K., Farritor, S., 2007. “Mechanical Design of Robotic In vivo Wheeled Mobility”. ASME Journal of Mechanical Design, 129(10), October, pp. 1037-104.) These robots have been used to enhance the ability of laparoscopic surgeons to visualize the surgical field (M., Hadzialic, A., Dumpert, J., Platt, S. R., Farritor, S., and Oleynikov, D., 2004. “In vivo Robots for Laparoscopic Surgery”. Studies in Health Technology and Informatics, 98, pp. 316-322; and Rentschler, M., Dumpert, J., Platt, S. R., Farritor, S., and Oleynikov, D., 2006. “Mobile In vivo Robots Can Assist In Abdominal Exploration”. Surg. Endosc., 20(1), January, pp. 135-138), and to obtain tissue samples during a single-port liver biopsy in a porcine model. (Rentschler, M., Dumpert, J., Platt, S. R., Iagnemma, K., Oleynikov, D., and Farritor, S., 2007. “An In vivo Mobile Robot for Surgical Vision and Task Assistance”. ASME Journal of Medical Devices, 1, pp. 23-29.)
In Vivo Gastrointestinal Robots
While this work has shown that in vivo mobility is possible, some such designs will be ineffective in un-insufflated cavities and cylindrical lumens (i.e. GI tract) where fundamentally different mobility approaches and designs are needed. In addition, insufflation in remote/trauma situations is extremely limited due to lack of equipment, and especially in cases where cavity trauma wounds may prevent proper sealing. Thus, an in vivo robot must also be able to traverse an uninsufflated cavity in order to be effective in remote/trauma environments.
The simplest such developed in vivo robotic mechanisms for the GI tract have been maneuverable endoscopes for colonoscopy and laparoscopy (Fukuda, T., Guo, S., Kosuge, K., Arai, F., Negoro, M., Nakabayashi, K., 1994. “Micro Active Catheter System with Multi Degrees of Freedom”. Proceedings of the IEEE International Conference on Robotics and Automation, San Diego, Calif., 3, pp. 2290-2295; and Suzumori, K., Iikura, S., Tanaka, H., 1991. “Development of Flexible Microactuator and its Applications to Robotics Mechanisms,” Proceedings of the IEEE International Conference on Robotics and Automation, Sacramento, Calif., 2, pp. 1622-1627.) These devices possess actuators to rotate the endoscope tip after it enters the body. Other in vivo robots have been developed to explore hollow cavities (e.g., the colon or esophagus) with locomotion systems based on ‘inch-worm’ motion that use a series of grippers and extensors (Phee, L, Accoto, D., Menciassi, A., Stefanini, C., Carrozza, M., Dario, P, 2002. “Analysis and Development of Locomotion Devices for the Gastrointestinal Tract”. IEEE Transaction on Biomedical Engineering, 49(6), June, pp. 613-616), rolling tracks (Flynn, A., Udayakumar, K., Barret, D., et al, 1995. “Tomorrow's Surgery; Micro-motors and Microrobots for Minimally Invasive Procedures”. Minimally Invasive Surgery & Allied Technologies, 7(4), April, pp. 343-52), rolling stents (Breedveld, P., Danielle, E., Van Gorp, M., 2004. “Locomotion through the Intestine by means of Rolling Stents”. Proceedings of the ASME Design Engineering Technical Conferences, Salt Lake City, Utah), or the rotational motion of a spiral-shaped body (Kim, Y. T., and Kim, D. E., 2010. “Novel Propelling Mechanisms Based on Friction Interaction for Endoscopic Robot”. Tribology Transactions, 53(2), March, pp. 203-211). These devices apply radial pressure to the walls of the hollow cavities they explore. Dario et al. have recently described an endoscopic pill with an active locomotion system that uses legs to push against the gastrointestinal walls (Stefanini, C., Menciassi, A, and Dario, P., 2006. “Modeling and Experiments on a Legged Microrobot Locomoting in a Tubular, Compliant and Slippery Environment”. The International Journal of Robotics Research, 25(5-6), May, pp. 551-560; Menciassi, A., Stefanini, C., Gorini, S., Pernorio, G., Kim, B., Park, J. O., Dario, P., 2004. “Locomotion of a Legged Capsule in the Gastrointestinal Tract: Theoretical Study and Preliminary Technological Results”. IEEE Int. Conf. on Engineering in Medicine and Biology, San Francisco, Calif., pp. 2767-2770; and Valdastri, P., Webster, R. J., Quaglia, C., Quirini, M., Menciassi, A., and Dario, P., 2009. “A New Mechanism for Mesoscale Legged Locomotion in Compliant Tubular Environments”. IEEE Transactions on Robotics, 25(5), October, pp. 1047-1057), a system that uses an external magnetic field to move the device through the intestine (Ciuti, G., Valdastri, P., Menciassi, A., and Dario, P., 2010. “Robotic magnetic steering and locomotion of capsule endoscope for diagnostic and surgical endoluminal procedures”. Robotica, 28(2), March, pp. 199-207), a system that combines the two aforementioned systems (Simi, M., Valdastri, P., Quaglia, C., Menciassi, A., and Dario, P., 2010. “Design, Fabrication, and Testing of a Capsule With Hybrid Locomotion for Gastrointestinal Tract Exploration”. IEEE/ASME Transactions on Mechatronics, 15(2), April, pp. 170-180), and a clamping system that uses shape memory alloys (Menciassi, A., Moglia, A., Gorini, S., Pernorio, G., Stefanini, C., and Dario, P., 2005. “Shape Memory Alloy Clamping Devices of a Capsule for Monitoring Tasks in the Gastrointestinal Tract”. J. Micromech Microeng, 15(1), January, pp. 2045-2055.) Additionally, Dario et al. have described a modular robot that enters the body in subsections through the mouth, assembles itself within the gastric cavity for a surgical task, and then disassembles itself upon completion of the task for natural excretion (Harada, K., Oetomo, D., Susilo, E., Menciassi, A., Daney, D., Merlet, J., and Dario, P., 2010. “A reconfigurable modular robotic endoluminal surgical system: vision and preliminary results”. Robotica, 28(2), March, pp. 171-183.)